Cement with resilient latex polymer

ABSTRACT

Compositions comprising: (i) a hydraulic cement; and (ii) a polymer comprising at least one monomer having an oxazoline group. Methods of cementing in a well comprising: (A) forming a hydraulic cement composition comprising: (i) a hydraulic cement; (ii) a polymer comprising at least one monomer having an oxazoline group; and (iii) water; (B) introducing the hydraulic cement composition into the well.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. application Ser. No. 15/031,924 filed onApr. 25, 2016, entitled “Cement with Resilient Latex Polymer,” which isa U.S. National Stage Application of International Application No.PCT/US2013/071627 filed Nov. 25, 2013, entitled “Cement with ResilientLatex Polymer,” the entire disclosures of which are each herebyincorporated by reference.

TECHNICAL FIELD

The disclosure is in the field of producing crude oil or natural gasfrom subterranean formations. More specifically, the disclosuregenerally relates to compositions and methods for cementing in a well.

BACKGROUND

In a primary cementing operation in a well, a hydraulic cementcomposition is pumped into an annular space between the wall of thewellbore and the casing. The set cement sheath supports the casing andbonds with the wellbore. The set cement sheath prevents the migration offluids and gas outside the casing toward the surface of the well.

The set cement sheath must be capable of sustaining high hydrostaticpressure in order to achieve effective zonal isolation. The sheath mayfail due to stresses induced by high fluid pressures or hightemperatures inside the casing. A high internal pressure results inexpansion of the casing, which can cause cracks in the sheath.Similarly, a set cement sheath may be subjected to stresses and fail asa result of creeping of the surrounding subterranean formation.

In order to overcome the stress induced cement failure, elastomericparticulates have been incorporated in the cement composition to enhancethe resiliency. Since these materials are solid particles and have aparticle size larger than that of the hydraulic cement, silica, andother cement additives, they increase the slurry viscosity.

In general, liquid additives are preferred in some field locations andoff shore fields. A copolymer of styrene-butadiene in liquid form(styrene-butadiene latex) is an additive for cement known to increasethe resiliency of the set cement to some extent; however, greaterresiliency than can be provided by styrene-butadiene latex is desired.Therefore, there is a need to identify a liquid composition that canprovide better resiliency to a set hydraulic cement composition.

SUMMARY OF THE DISCLOSURE

Compositions are disclosed, the compositions comprising: (i) a hydrauliccement; and (ii) a polymer comprising at least one monomer having anoxazoline group.

Methods of cementing in a well are disclosed, the methods comprising:(A) forming a hydraulic cement composition comprising: (i) a hydrauliccement; (ii) a polymer comprising at least one monomer having anoxazoline group; and (iii) water; (B) introducing the hydraulic cementcomposition into the well.

In various embodiments, the polymer is in a liquid or solid form. Forexample, if insoluble in water, microparticles of such a polymer inliquid form can be dispersed in water, which can form a latex.

In various embodiments, the polymer comprises at least one mono-vinylmonomer and at least one di-vinyl monomer. For example, the mono-vinylmonomer can be selected from the group consisting of: acrylic acid,methacrylic acid, acrylic acid esters, methacrylic acid esters,2-isopropenyl-2-oxazoline, styrene, acrylonitrile, alkyl vinyl ethers,and alkoxy vinyl ethers. The di-vinyl monomer can be selected from thegroup consisting of: alkane diol diacrylates, alkane dioldimethacrylates, alkene glycol diacrylates, alkene glycoldimethacrylates, alkane diol divinyl ethers, alkene glycoldivinylethers, divinylbenzene, allyl methacrylate, and allyl acrylate.

In various embodiments, the polymer is in a solid particulate form of across-linked copolymer of styrene, butyl acrylate, divinylbenzene, and2-isopropenyl-2-oxazoline (“SBDI”). In various embodiments, the molarproportions of the monomers in the copolymer are in the range of styreneabout 10% to about 35%, butyl acrylate about 25% to about 60%,divinylbenzene about 2% to about 15%, and 2-isopropenyl-2-oxazolineabout 10 to about 40%. Such a polymer may control fluid loss duringpumping of a hydraulic cement composition and provides greaterresiliency to the hydraulic cement composition after it sets.

In some embodiments, hydraulic cement compositions with such an SBDIpolymer are provided. In addition, in some embodiments methods ofcementing in a well are provided using such hydraulic cementcompositions.

An SBDI latex was tested in a cement slurry for fluid control andmechanical properties, the experiment and results are discussed below.Such an SBDI latex can provide one or more of the following advantagesin a hydraulic cement composition: (a) control fluid loss during pumpinginto a well; and (b) provide greater resiliency to the set cement thanstyrene-butadiene latex.

Without necessarily being limited by any theory, it is presentlybelieved that a polymeric material including a monomer having anoxazoline group can provide one or more of such benefits when used in acement composition.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing is incorporated into the specification to helpillustrate examples according to a presently preferred embodiment of thedisclosure.

FIG. 1 is a thickening time chart for a hydraulic cement compositioncomprising styrene-butadiene latex (Slurry Design F).

FIG. 2 is a thickening time chart for a hydraulic cement compositioncomprising SBDI latex (Slurry Design G).

FIG. 3 is a thickening time chart for a hydraulic cement compositioncomprising styrene-butadiene latex (Slurry Design H).

FIG. 4 is a thickening time chart for a hydraulic cement compositioncomprising SBDI latex (Slurry Design I).

FIG. 5 is a UCA chart of compressive strength for a hydraulic cementcomposition comprising styrene-butadiene latex (Slurry Design H).

FIG. 6 is a UCA chart of compressive strength for a hydraulic cementcomposition comprising SBDI latex (Slurry Design I).

FIG. 7 is an axial and radial strain analysis of a hydraulic cementcomposition comprising styrene-butadiene latex (Slurry Design H).

FIG. 8 is an axial and radial strain analysis of a hydraulic cementcomposition comprising SBDI latex (Slurry Design I).

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS AND BEST MODE

Definitions and Usages

General Interpretation

The words or terms used herein have their plain, ordinary meaning in thefield of this disclosure, except to the extent explicitly and clearlydefined in this disclosure or unless the specific context otherwiserequires a different meaning.

The words “comprising,” “containing,” “including,” “having,” and allgrammatical variations thereof are intended to have an open,non-limiting meaning. For example, a composition comprising a componentdoes not exclude it from having additional components, an apparatuscomprising a part does not exclude it from having additional parts, anda method having a step does not exclude it having additional steps. Whensuch terms are used, the compositions, apparatuses, and methods that“consist essentially of” or “consist of” the specified components,parts, and steps are specifically included and disclosed. As usedherein, the words “consisting essentially of,” and all grammaticalvariations thereof are intended to limit the scope of a claim to thespecified materials or steps and those that do not materially affect thebasic and novel characteristic(s) of the present disclosure.

The indefinite articles “a” or “an” mean one or more than one of thecomponent, part, or step that the article introduces.

Each numerical value should be read once as modified by the term “about”(unless already expressly so modified), and then read again as not somodified, unless otherwise indicated in context.

Whenever a numerical range of degree or measurement with a lower limitand an upper limit is disclosed, any number and any range falling withinthe range is also intended to be specifically disclosed. For example,every range of values (in the form “from a to b,” or “from about a toabout b,” or “from about a to b,” “from approximately a to b,” and anysimilar expressions, where “a” and “b” represent numerical values ofdegree or measurement) is to be understood to set forth every number andrange encompassed within the broader range of values.

Oil and Gas Reservoirs

In the context of production from a well, “oil” and “gas” are understoodto refer to crude oil and natural gas, respectively. Oil and gas arenaturally occurring hydrocarbons in certain subterranean formations.

A “subterranean formation” is a body of rock that has sufficientlydistinctive characteristics and is sufficiently continuous forgeologists to describe, map, and name it.

A subterranean formation having a sufficient porosity and permeabilityto store and transmit fluids is sometimes referred to as a “reservoir.”

A subterranean formation containing oil or gas may be located under landor under the seabed off shore. Oil and gas reservoirs are typicallylocated in the range of a few hundred feet (shallow reservoirs) to a fewtens of thousands of feet (ultra-deep reservoirs) below the surface ofthe land or seabed.

Well Servicing and Fluids

To produce oil or gas from a reservoir, a wellbore is drilled into asubterranean formation, which may be the reservoir or adjacent to thereservoir. Typically, a wellbore of a well must be drilled hundreds orthousands of feet into the earth to reach a hydrocarbon-bearingformation.

Generally, well services include a wide variety of operations that maybe performed in oil, gas, geothermal, or water wells, such as drilling,cementing, completion, and intervention. Well services are designed tofacilitate or enhance the production of desirable fluids such as oil orgas from or through a subterranean formation. A well service usuallyinvolves introducing a fluid into a well.

Drilling is the process of drilling the wellbore. After a portion of thewellbore is drilled, sections of steel pipe, referred to as casing,which are slightly smaller in diameter than the borehole, are placed inat least the uppermost portions of the wellbore. The casing providesstructural integrity to the newly drilled borehole.

Cementing is a common well operation. For example, hydraulic cementcompositions can be used in cementing operations in which a string ofpipe, such as casing or liner, is cemented in a wellbore. The cementstabilizes the pipe in the wellbore and prevents undesirable migrationof fluids along the annulus between the wellbore and the outside of thecasing or liner from one zone along the wellbore to the next. Where thewellbore penetrates into a hydrocarbon-bearing zone of a subterraneanformation, the casing can later be perforated to allow fluidcommunication between the zone and the wellbore. The cemented casingalso enables subsequent or remedial separation or isolation of one ormore production zones of the wellbore by using downhole tools, such aspackers or plugs, or by using other techniques, such as forming sandplugs or placing cement in the perforations. Hydraulic cementcompositions can also be utilized in intervention operations, such as inplugging highly permeable zones, or fractures in zones, that may beproducing too much water, plugging cracks or holes in pipe strings, andthe like.

Completion is the process of making a well ready for production orinjection. This principally involves preparing a zone of the wellbore tothe required specifications, running in the production tubing andassociated downhole equipment, as well as perforating and stimulating asrequired.

Intervention is any operation carried out on a well during or at the endof its productive life that alters the state of the well or wellgeometry, provides well diagnostics, or manages the production of thewell.

Wells

A “well” includes a wellhead and at least one wellbore from the wellheadpenetrating the earth. The “wellhead” is the surface termination of awellbore, which surface may be on land or on a seabed.

A “well site” is the geographical location of a wellhead of a well. Itmay include related facilities, such as a tank battery, separators,compressor stations, heating or other equipment, and fluid pits. Ifoffshore, a well site can include a platform.

The “wellbore” refers to the drilled hole, including any cased oruncased portions of the well or any other tubulars in the well. The“borehole” usually refers to the inside wellbore wall, that is, the rocksurface or wall that bounds the drilled hole. A wellbore can haveportions that are vertical, horizontal, or anything in between, and itcan have portions that are straight, curved, or branched. As usedherein, “uphole,” “downhole,” and similar terms are relative to thedirection of the wellhead, regardless of whether a wellbore portion isvertical or horizontal.

As used herein, introducing “into a well” means introducing at leastinto and through the wellhead. According to various techniques known inthe art, tubulars, equipment, tools, or fluids can be directed from thewellhead into any desired portion of the wellbore.

As used herein, the word “tubular” means any kind of structural body inthe general form of a tube. Tubulars can be of any suitable bodymaterial, but in the oilfield they are most commonly of steel. Examplesof tubulars in oil wells include, but are not limited to, a drill pipe,a casing, a tubing string, a line pipe, and a transportation pipe.

As used herein, the term “annulus” means the space between two generallycylindrical objects, one inside the other. The objects can be concentricor eccentric. Without limitation, one of the objects can be a tubularand the other object can be an enclosed conduit. The enclosed conduitcan be a wellbore or borehole or it can be another tubular. Thefollowing are some non-limiting examples illustrating some situations inwhich an annulus can exist. Referring to an oil, gas, or water well, inan open hole well, the space between the outside of a tubing string andthe borehole of the wellbore is an annulus. In a cased hole, the spacebetween the outside of the casing and the borehole is an annulus. Inaddition, in a cased hole there may be an annulus between the outsidecylindrical portion of a tubular, such as a production tubing string,and the inside cylindrical portion of the casing. An annulus can be aspace through which a fluid can flow or it can be filled with a materialor object that blocks fluid flow, such as a packing element. Unlessotherwise clear from the context, as used herein an “annulus” is a spacethrough which a fluid can flow.

A fluid can be, for example, a drilling fluid, a setting compositionsuch as a hydraulic cement composition, a treatment fluid, or a spacerfluid.

In the context of a well or wellbore, a “portion” or “interval” refersto any downhole portion or interval along the length of a wellbore.

A “zone” refers to an interval of rock along a wellbore that isdifferentiated from uphole and downhole zones based on hydrocarboncontent or other features, such as permeability, composition,perforations or other fluid communication with the wellbore, faults, orfractures. A zone of a wellbore that penetrates a hydrocarbon-bearingzone that is capable of producing hydrocarbon is referred to as a“production zone.” A “treatment zone” refers to a zone into which afluid is directed to flow from the wellbore. As used herein, “into atreatment zone” means into and through the wellhead and, additionally,through the wellbore and into the treatment zone.

As used herein, a “downhole” fluid is an in-situ fluid in a well, whichmay be the same as a fluid at the time it is introduced, or a fluidmixed with another fluid downhole, or a fluid in which chemicalreactions are occurring or have occurred in-situ downhole.

Fluid loss refers to the undesirable leakage of a fluid phase of anytype of fluid into the permeable matrix of a zone, which zone may or maynot be a treatment zone.

Generally, the greater the depth of the formation, the higher the statictemperature and pressure of the formation. Initially, the staticpressure equals the initial pressure in the formation before production.After production begins, the static pressure approaches the averagereservoir pressure.

A “design” refers to the estimate or measure of one or more parametersplanned or expected for a particular fluid or stage of a well service ortreatment. For example, a fluid can be designed to have components thatprovide a minimum density or viscosity for at least a specified timeunder expected downhole conditions. A well service may include designparameters such as fluid volume to be pumped, required pumping time fora treatment, or the shear conditions of the pumping.

The term “design temperature” refers to an estimate or measurement ofthe actual temperature at the downhole environment during the time of atreatment. For example, the design temperature for a well treatmenttakes into account not only the bottom hole static temperature (“BHST”),but also the effect of the temperature of the fluid on the BHST duringtreatment. The design temperature for a fluid is sometimes referred toas the bottom hole circulation temperature (“BHCT”). Because fluids maybe considerably cooler than BHST, the difference between the twotemperatures can be quite large. Ultimately, if left undisturbed asubterranean formation will return to the BHST.

Phases, Physical States, and Materials

As used herein, “phase” is used to refer to a substance having achemical composition and physical state that is distinguishable from anadjacent phase of a substance having a different chemical composition ora different physical state.

The word “material” refers to the substance, constituted of one or morephases, of a physical entity or object. Rock, water, air, metal, cementslurry, sand, and wood are all examples of materials. The word“material” can refer to a single phase of a substance on a bulk scale(larger than a particle) or a bulk scale of a mixture of phases,depending on the context.

As used herein, if not other otherwise specifically stated, the physicalstate or phase of a substance (or mixture of substances) and otherphysical properties are determined at a temperature of 77° F. (25° C.)and a pressure of 1 atmosphere (Standard Laboratory Conditions) withoutapplied shear.

Particles and Particulates

As used herein, a “particle” refers to a body having a finite mass andsufficient cohesion such that it can be considered as an entity buthaving relatively small dimensions. A particle can be of any sizeranging from molecular scale to macroscopic, depending on context.

A particle can be in any physical state. For example, a particle of asubstance in a solid state can be as small as a few molecules on thescale of nanometers up to a large particle on the scale of a fewmillimeters, such as large grains of sand. Similarly, a particle of asubstance in a liquid state can be as small as a few molecules on thescale of nanometers up to a large drop on the scale of a fewmillimeters. A particle of a substance in a gas state is a single atomor molecule that is separated from other atoms or molecules such thatintermolecular attractions have relatively little effect on theirrespective motions.

As used herein, particulate or particulate material refers to matter inthe physical form of distinct particles in a solid or liquid state(which means such an association of a few atoms or molecules). As usedherein, a particulate is a grouping of particles having similar chemicalcomposition and particle size ranges anywhere in the range of about 0.5micrometer (500 nm), for example, microscopic clay particles, to about 3millimeters, for example, large grains of sand.

A particulate can be of solid or liquid particles. As used herein,however, unless the context otherwise requires, particulate refers to asolid particulate. Of course, a solid particulate is a particulate ofparticles that are in the solid physical state, that is, the constituentatoms, ions, or molecules are sufficiently restricted in their relativemovement to result in a fixed shape for each of the particles.

Polymers and Latex

As used herein, unless the context otherwise requires, a “polymer” or“polymeric material” includes homopolymers, copolymers, terpolymers,etc. In addition, the term “copolymer” as used herein is not limited tothe combination of polymers having two monomeric units, but includes anycombination of monomeric units, for example, terpolymers, tetrapolymers,etc.

It should be understood, of course, that a polymer is formed by achemical reaction of one or more monomers. A polymer having orcomprising one or more monomers is understood to refer to being formedfrom the one or more monomers.

Latex is the stable dispersion (emulsion) of polymer microparticles inan aqueous medium. A latex may be natural or synthetic. A latex can bemade synthetically, for example, by polymerizing a monomer such asstyrene that has been emulsified with surfactants.

Dispersions

A dispersion is a system in which particles of a substance of onechemical composition and physical state are dispersed in anothersubstance of a different chemical composition or physical state. Inaddition, phases can be nested. If a substance has more than one phase,the most external phase is referred to as the continuous phase of thesubstance as a whole, regardless of the number of different internalphases or nested phases.

Fluids

A fluid can be a homogeneous or heterogeneous. In general, a fluid is anamorphous substance that is or has a continuous phase of particles thatare smaller than about 1 micrometer that tends to flow and to conform tothe outline of its container.

Every fluid inherently has at least a continuous phase. A fluid can havemore than one phase. For example, a fluid can be in the form of asuspension or slurry (solid particles dispersed in a liquid phase), anemulsion (liquid particles dispersed in another liquid phase), or a foam(a gas phase dispersed in a liquid phase).

General Measurement Terms

Unless otherwise specified or unless the context otherwise clearlyrequires, any ratio or percentage means by weight.

Unless otherwise specified or unless the context otherwise clearlyrequires, the phrase “by weight of cement” means by weight of thehydraulic cement.

If there is any difference between U.S. or Imperial units, U.S. unitsare intended. For example, “ppg” means pounds per U.S. gallon.

As used herein, a “sack” (“sk”) is an amount that weighs 94 pounds (94lb/sk).

As used herein, the conversion between gallon per sack (gal/sk) andpercent by weight of cement (% bwoc) is 1 gal/sk=3.96% bwoc.

Cementing and Hydraulic Cement Compositions

In a cementing operation, a hydraulic cement, water, and any othercomponents are mixed to form a hydraulic cement composition in fluidform. The hydraulic cement composition is pumped as a fluid (typicallyin the form of suspension or slurry) into a desired location in thewellbore.

For example, in cementing a casing or liner, the hydraulic cementcomposition is pumped into the annular space between the exteriorsurfaces of a pipe string and the borehole (that is, the wall of thewellbore). The hydraulic cement composition should be a fluid for asufficient time before setting to allow for pumping the composition intothe wellbore and for placement in a desired downhole location in thewell. The cement composition is allowed time to set in the annularspace, thereby forming an annular sheath of hardened, substantiallyimpermeable cement. The hardened cement supports and positions the pipestring in the wellbore and fills the annular space between the exteriorsurfaces of the pipe string and the borehole of the wellbore.Consequently, oil or gas can be produced in a controlled manner bydirecting the flow of oil or gas through the casing and into thewellhead.

Cement compositions can also be used, for example, in well-pluggingoperations or gravel-packing operations. Cement compositions can also beused to control fluid loss or migration in zones.

Cement and Cement Compositions

In the most general sense of the word, a “cement” is a binder, that is,a substance that sets and can bind other materials together. As usedherein, “cement” refers to an inorganic cement that, when mixed withwater, will begin to set and harden into a concrete material.

As used herein, a “cement composition” is a material including at leastone inorganic cement. A cement composition can also include additives.Some cement compositions can include water or be mixed with water.Depending on the type of cement, the chemical proportions, when a cementcomposition is mixed with water it can begin setting to form a solidmaterial.

A cement can be characterized as non-hydraulic or hydraulic.

Non-hydraulic cements (for example, gypsum plaster, Sorel cements) mustbe kept dry in order to retain their strength. A non-hydraulic cementproduces hydrates that are not resistant to water. If the proportion ofwater to a non-hydraulic cement is too high, the cement composition willnot set into a hardened material.

Hydraulic cements (for example, Portland cement) harden because ofhydration, chemical reactions that occur independently of the mixture'swater content; they can harden even underwater or when constantlyexposed to wet weather. The chemical reaction that results when the drycement powder is mixed with water produces hydrates that have extremelylow solubility in water.

More particularly, Portland cement is formed from a clinker such as aclinker according to the European Standard EN197-1: “Portland cementclinker is a hydraulic material which shall consist of at leasttwo-thirds by mass of calcium silicates (3 CaO.SiO2 and 2 CaO.SiO2), theremainder consisting of aluminium- and iron-containing clinker phasesand other compounds. The ratio of CaO to SiO2 shall not be less than2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass.”The American Society of Testing Materials (“ASTM”) standard “C 150”defines Portland cement as “hydraulic cement (cement that not onlyhardens by reacting with water but also forms a water-resistant product)produced by pulverizing clinkers consisting essentially of hydrauliccalcium silicates, usually containing one or more of the forms ofcalcium sulfate as an inter ground addition.” In addition, Portlandcements typically have a ratio of CaO to SiO₂ of less than 4.0.

The American Society for Testing and Materials (ASTM) has established aset of standards for a Portland cement to meet to be considered an ASTMcement. These standards include Types I, II, III, IV, and V.

The American Petroleum Institute (API) has established a set ofstandards that a Portland cement must meet to be considered an APIcement. The standards include Classes A, B, C, D, E, F, G, H, I, and J.

Slag cement (also known as ground granulated blast-furnace slag or“GGBFS”, is a low CaO cement. As used herein, slag cement has a ratio ofCaO to SiO2 that is less than 1.0.

A blended cement is a hydraulic cement produced by intergrindingPortland cement clinker with other materials, by blending Portlandcement with other materials, or by a combination of intergrinding andblending.

Cement Additives

A common additive is silica (silica dioxide). Silica is commonly addedas a strength-stabilizing agent for the set cement. SSA-1™ agent (alsocalled silica flour) is a powdered sand that helps oilwell cementmaintain low permeability and high compressive strength underhigh-temperature conditions. SSA-1™ agent is recommended for use incementing wells where static temperatures exceed 230° F. Above thistemperature, most cement compositions exhibit satisfactory compressivestrength after the initial set but will rapidly lose strength aftercontinued exposure to high temperatures. SSA-1™ agent helps prevent thisproblem by chemically reacting with the cement at high temperatures.SSA-1™ agent has been widely used in thermal recovery wells incombination with refractory-type cements. SSA-1™ agent is mined andprocessed in the following two forms: (a) in a minus 200-mesh powder formaximum reactivity in cement concentrations of normal weight; and (b) ina selected particle-gradation design for densified cements whereincreased weights and maximum reactivity are required.

Fly ash is made from burned coal and is a common additive in cementcompositions. POZMIX™ pozzolanic cement additive is a fly ash made fromburned coal. This additive helps lighten the slurry and enhance itspumping properties. This additive can be used at bottomhole temperatures(BHTs) between 80° F. and 550° F. (27° C. to 288° C.). Typical hydrauliccement slurries with POZMIX™ additive are 50/50 blends of POZMIX™additive and hydraulic cement. POZMIX™ additive is compatible with allclasses of hydraulic cement. It also reacts with lime to produce acement-like material. MICRO FLY ASH™ pozzolanic cement additive is a flyash with a particle size from 3 micrometer to 9 micrometer. MICRO FLYASH™ pozzolanic cement additive is commercially available fromHalliburton Energy Services, Inc. in Duncan, Okla.

Cement compositions can contain other additives, including but notlimited to resins, latex, stabilizers, microspheres, aqueoussuperabsorbers, viscosifying agents, suspending agents, dispersingagents, salts, accelerants, surfactants, retarders, defoamers,high-density materials, low-density materials, fluid-loss controlagents, elastomers, vitrified shale, gas migration control additives,formation conditioning agents, or other additives or modifying agents,or combinations thereof.

An example of an additive is a high-density additive. As used herein, a“high-density” additive is an additive that has a density greater than 3g/cm³. Some metal oxides can be used as a high-density additive. As usedherein, a “metal oxide” is a metal cation or transition metal cationwith an oxide anion. Examples of metal oxides include, but are notlimited to, iron oxide (Fe₂O₃) and manganese oxide (Mn₃O₄). Acommercially available example of an iron oxide high-density additive isHI-DENSE™ and an example of a commercially available manganese oxide isMICROMAX™, both available from Halliburton Energy Services, Inc. inDuncan, Okla.

For example, MICROMAX™ weight additive increases slurry density withhausmannite ore ground to an average particle size of 5 microns. Unlikemost weighting materials, MICROMAX™ weight additive remains insuspension when added directly to mixing water. MICROMAX™ weightadditive can be used at bottomhole circulating temperatures between 80°F. and 500° F. (27° C. to 260° C.). In deep wells with high temperaturesand pressures, MICROMAX™ weight additive can help restrain formationpressures and improve mud displacement. Additive concentrations dependon the slurry weight designed for individual wells. Because of thefine-ground ore in MICROMAX™ weight additive, higher concentrations ofretarders might be required to achieve the thickening times provided byother types of weight additives. Slurries of cement compositionscontaining MICROMAX™ weight additive might also require the addition ofdispersants. MICROMAX™ weight additive is commercially available fromHalliburton Energy Services, Inc. in Duncan, Okla.

Of course, additives should be selected for not interfering with thepurpose of the fluid.

Pumping Time and Thickening Time

During placement of a cement composition, it is necessary for the cementcomposition to remain pumpable during introduction into the subterraneanformation or the well and until the cement composition is situated inthe portion of the subterranean formation or the well to be cemented.After the cement composition has reached the portion of the well to becemented, the cement composition ultimately sets. A cement compositionthat thickens too quickly while being pumped can damage pumpingequipment or block tubing or pipes, and a cement composition that setstoo slowly can cost time and money while waiting for the cementcomposition to set.

As used herein, the “pumping time” is the total time required forpumping a hydraulic cementing composition into a desired portion or zoneof the well in a cementing operation plus a safety factor.

As used herein, the “thickening time” is how long it takes for a cementcomposition to become unpumpable at a specified temperature andspecified pressure. The pumpability of a cement composition is relatedto the consistency of the composition. The consistency of a cementcomposition is measured in Bearden units of consistency (Bc), adimensionless unit with no direct conversion factor to the more commonunits of viscosity. As used herein, a setting fluid is considered to be“pumpable” so long as the fluid has an apparent viscosity less than30,000 mPa·s (cP) (independent of any gel characteristic) or aconsistency of less than 70 Bc. A setting fluid becomes “unpumpable”when the consistency of the composition reaches at least 70 Bc.

As used herein, the consistency of a cement composition is measuredaccording to ANSI/API Recommended Practice 10B-2 as follows. The cementcomposition is mixed and then placed in the test cell of aHigh-Temperature, High-Pressure (HTHP) consistometer, such as a FANN™Model 275 or a CHANDLER™ Model 8240. The cement composition is tested inthe HTHP consistometer at the specified temperature and pressure.Consistency measurements are taken continuously until the consistency ofthe cement composition exceeds 70 Bc.

Of course, the thickening time should be greater than the pumping timefor a cementing operation.

Setting and Compressive Strength

As used herein, the term “set” means the process of becoming solid andhard by curing.

Depending on the composition and the conditions, it can take just a fewminutes up to 72 hours or longer for some cement compositions toinitially set. A cement composition sample that is at least initiallyset is suitable for destructive compressive strength testing.

Compressive strength is defined as the capacity of a material towithstand axially directed pushing forces. The compressive strength asetting composition attains is a function of both curing time andtemperature, among other things.

The compressive strength of a cement composition can be used to indicatewhether the cement composition has set. As used herein, a cementcomposition is considered “initially set” when the cement compositionhas developed a compressive strength of 50 psi (345 kPa) using thenon-destructive compressive strength method. As used herein, the“initial setting time” is the difference in time between when the cementis mixed with water and when the cement composition is initially set.Some cement compositions can continue to develop a compressive strengthgreater than 50 psi (345 kPa) over the course of several days. Thecompressive strength of certain kinds of cement compositions can reachover 10,000 psi (70,000 kPa).

Compressive strength is typically measured at a specified time after thecement composition has been mixed and at a specified temperature andpressure conditions. If not otherwise stated, the setting and theinitial setting time is determined at a temperature of 212° F. (100° C.)and an atmospheric pressure of 3,000 psi (20,700 kPa). Compressivestrength can also be measured at a specific time and temperature afterthe cement composition has been mixed, for example, in the range ofabout 24 to about 72 hours at a design temperature and pressure, forexample, a temperature of 212° F. (100° C.) and 3,000 psi (20,700 kPa).According to ANSI/API Recommended Practice 10B-2, compressive strengthcan be measured by either a destructive method or non-destructivemethod.

The destructive method mechanically tests the strength of cementcomposition samples at various points in time by crushing the samples ina compression-testing machine. The destructive method is performed asfollows. The cement composition is mixed and then cured. The curedcement composition sample is placed in a compressive strength testingdevice, such as a Super L Universal testing machine model 602, availablefrom Tinius Olsen, Horsham in Pennsylvania, USA. According to thedestructive method, the compressive strength is calculated as the forcerequired to break the sample divided by the smallest cross-sectionalarea in contact with the load-bearing plates of the compression device.The actual compressive strength is reported in units of pressure, suchas pound-force per square inch (psi) or megapascals (MPa).

The non-destructive method continually measures a correlated compressivestrength of a cement composition sample throughout the test period byutilizing a non-destructive sonic device such as an Ultrasonic CementAnalyzer (UCA) available from Fann Instruments in Houston, Tex. As usedherein, the “compressive strength” of a cement composition is measuredutilizing an Ultrasonic Cement Analyzer as follows. The cementcomposition is mixed. The cement composition is placed in an UltrasonicCement Analyzer, in which the cement composition is heated to thespecified temperature and pressurized to the specified pressure. The UCAcontinually measures the transit time of the acoustic signal through thesample. The UCA device contains preset algorithms that correlate transittime through the sample to compressive strength. The UCA reports thecompressive strength of the cement composition in units of pressure,such as psi or megapascals (MPa).

Cement Testing Conditions

As used herein, if any test (for example, thickening time or compressivestrength) requires the step of mixing the setting composition, cementcomposition, or the like, then the mixing step is performed according toANSI/API Recommended Practice 10B-2 as follows. Any of the ingredientsthat are a dry particulate substance are pre-blended. The liquid isadded to a mixing container and the container is then placed on a mixerbase. For example, the mixer can be a Lightning Mixer. The motor of thebase is then turned on and maintained at about 4,000 revolutions perminute (rpm). The pre-blended dry ingredients are added to the containerat a uniform rate in not more than 15 seconds (s). After all the dryingredients have been added to the liquid ingredients in the container,a cover is then placed on the container, and the composition is mixed at12,000 rpm (+/−500 rpm) for 35 s (+/−1 s). It is to be understood thatthe composition is mixed under Standard Laboratory Conditions (about 77°F. and about 1 atmosphere pressure).

It is also to be understood that if any test (for example, thickeningtime or compressive strength) specifies the test be performed at aspecified temperature and possibly a specified pressure, then thetemperature and pressure of the cement composition is ramped up to thespecified temperature and pressure after being mixed at ambienttemperature and pressure. For example, the cement composition can bemixed at 77° F. (25° C.) and then placed into the testing apparatus andthe temperature of the cement composition can be ramped up to thespecified temperature. As used herein, the rate of ramping up thetemperature is in the range of about 3° F./min to about 5° F./min. Afterthe cement composition is ramped up to the specified temperature andpossibly pressure, the cement composition is maintained at thattemperature and pressure for the duration of the testing.

As used herein, if any test (for example, compressive strength) requiresthe step of “curing the cement composition” or the like, then the curingstep is performed according to ANSI/API Recommended Practice 10B-2 asfollows. After the cement composition has been mixed, it is poured intoa curing mold. The curing mold is placed into a pressurized curingchamber and the curing chamber is maintained at a temperature of 212° F.(100° C.) and a pressure of 3,000 psi (20,700 kPa). The cementcomposition is allowed to cure for the length of time necessary for thecomposition to set. After the composition has set, the curing mold isplaced into a water cooling bath until the cement composition sample istested.

Cement Retarders and Intensifiers

It is important to maintain a cement in a pumpable slurry state until itis placed in a desired portion of the well. For this purpose, a setretarder can be used in a cement slurry, which retards the settingprocess and provides adequate pumping time to place the cement slurry.Alternatively or in addition, a set intensifier can be used, whichaccelerates the setting process. The use of retarder or intensifier canbe used to help control the thickening time or setting of a cementcomposition.

Without being limited by any theory, it is believed a retarder works byone or more of the principles of chelation, adsorption, orprecipitation.

The selection of retarder depends upon the well temperature. Inaddition, different retarding of thickening time can be achieved atparticular temperature by varying the concentration of the retarder inthe cement composition. Some of the retarders work at a low temperaturerange while others work at high temperature range.

As used herein, a “retarder” is a chemical agent used to increase thethickening time of a cement composition. The need for retarding thethickening time of a cement composition tends to increase with depth ofthe zone to be cemented due to the greater time required to complete thecementing operation and the effect of increased temperature on thesetting of the cement. A longer thickening time at the designtemperature allows for a longer pumping time that may be required.

Method of Cementing in a Well

According to another embodiment of the disclosure, a method of treatinga well, is provided, the method including the steps of: forming ahydraulic cement composition (as a slurry) according to the disclosure;and introducing the composition into the well.

Forming Fluid

A fluid can be prepared at the job site, prepared at a plant or facilityprior to use, or certain components of the fluid can be pre-mixed priorto use and then transported to the job site. Certain components of thefluid may be provided as a “dry mix” to be combined with fluid or othercomponents prior to or during introducing the fluid into the well.

In certain embodiments, the preparation of a fluid can be done at thejob site in a method characterized as being performed “on the fly.” Theterm “on-the-fly” is used herein to include methods of combining two ormore components wherein a flowing stream of one element is continuouslyintroduced into flowing stream of another component so that the streamsare combined and mixed while continuing to flow as a single stream aspart of the on-going treatment. Such mixing can also be described as“real-time” mixing.

Introducing Into Well or Zone

Often the step of delivering a fluid into a well is within a relativelyshort period after forming the fluid, for example, less within 30minutes to one hour. More preferably, the step of delivering the fluidis immediately after the step of forming the fluid, which is “on thefly.”

It should be understood that the step of delivering a fluid into a wellcan advantageously include the use of one or more fluid pumps.

Introducing Below Fracture Pressure

In various embodiments, the step of introducing is at a rate andpressure below the fracture pressure of the treatment zone.

Allowing Time for Setting in the Well

After the step of introducing the cement composition into the well orzone, time is allowed for setting of the cement composition. Thispreferably occurs with time under the conditions in the zone of thesubterranean fluid.

Producing Hydrocarbon from Subterranean Formation

Preferably, after any such use of a fluid according to the disclosure, astep of producing hydrocarbon from the well or a particular zone is thedesirable objective.

Examples

To facilitate a better understanding of the present disclosure, thefollowing examples of certain aspects of some embodiments are given. Inno way should the following examples be read to limit, or define, theentire scope of the disclosure.

SBDI Latex

In the examples including SBDI latex, thestyrene-butylacrylate-divinylbenzene-2-isopropenyloxazoline latex hadthe following characteristics: appearance was that of a milky whiteemulsion; the solids content was 39.8%; the specific gravity was 1.05;the pH was 8.2; and the glass transition temperature was −58° F. (−50°C.).

Cement Slurry Designs

Hydraulic cement slurries A-E were prepared having a density of about16.8 ppg (2.01 kg/1) with a styrene butadiene latex or an SBDI latex andwith other additives as summarized in Table 1. The hydraulic cementslurries comprising styrene-butadiene latex were prepared for thepurpose of comparison to the slurries with SBDI latex.

TABLE 1 Slurry designs having density of 16.8 ppg (2.01 kg/l)Concentration Material Slurry Design A Slurry Design B Slurry Design CSlurry Design D Slurry Design E Water 26.32% bwoc 26.50% bwoc 26.54%bwoc 26.72% bwoc 24.71% bwoc Class H Cement 100.00 100.00 100.00 100.00100.00 Crystalline silica particulate 35.00% bwoc 35.00% bwoc 35.00%bwoc 35.00% bwoc 35.00% bwoc Cement retarder 0.80% bwoc 0.80% bwoc 0.4%bwoc 0.4% bwoc — Dispersant 0.05 gal/sk 0.05 gal/sk 0.02 gal/sk 0.02gal/sk 0.05 gal/sk Styrene-butadiene latex 2.00 gal/sk — 2.00 gal/sk — —SBDI latex — 2.00 gal/sk — 2.00 gal/sk 2.00 gal/sk NaCl — — — — 18 w/wStabilizer — — — 0.4 gal/sk Defoamer 0.02 gal/sk 0.02 gal/sk 0.02 gal/sk0.02 gal/sk 0.02 gal/sk

In addition, hydraulic cement slurries F-I were prepared having adensity of about 16.8 ppg (2.01 kg/l) with a styrene butadiene latex oran SBDI latex and with other additives as summarized in Table 2. Thehydraulic cement slurries comprising styrene-butadiene latex wereprepared for the purpose of comparison to the slurries with SBDI latex.

TABLE 2 Composition of the slurry having density of 16.8 ppg (2.01 kg/l)Concentration Material Slurry Design F Slurry Design G Slurry Design HSlurry Design I Water 27.25% bwoc 27.34% bwoc 18.47% bwoc 18.65% bwocClass H Cement 100 100 100 100 Dispersant 0.02 gal/sk 0.02 gal/sk 0.02gal/sk 0.02 gal/sk Styrene-butadiene latex 1 gal/sk — 2 gal/sk — SBDIlatex — 1 gal/sk — 2 gal/sk Defoamer 0.02 gal/sk 0.02 gal/sk 0.02 gal/sk0.02 gal/sk

Class H cement is a class of hydraulic cement. Other classes ofhydraulic cement may be used.

Crystalline silica particulate is preferably included in a hydrauliccement composition for cementing in a well. It can be included in therange of about 5% bwoc to about 50% bwoc, and is normally used in therange of about 10% bwoc to about 35% bwoc.

A cement retarder is optionally and commonly used in hydraulic cementslurries used for well application to increase the thickening time. Anexample of a cement retarder is a mixture of lignosulfonate and anorganic acid. Other examples of cement retarders included, withoutlimitation, organic acids, lignosulfonates, phosphates, phosphonates,sugars, carboxylic acid polymers, and borates. The concentration of acement retarder depends on the thickening time requirement. For example,a cement retarder can be included in the range of about 0.05% bwoc toabout 5% bwoc. Generally, a cement retarder can be used in the range ofabout 0.1% bwoc to about 3% bwoc.

A dispersant is optionally and commonly used in hydraulic cementslurries used for well applications. The dispersant in the presentexample was an organosulfur product. Other examples of dispersantsinclude, without limitation, polycarboxylate ethers and sulfonatedpolymers. For example, a dispersant can be included in the range ofabout 0.01 gallon per sack if cement (“gal/sk”) to about 0.1 gal/sk.

A defoamer is optionally and commonly used in hydraulic cement slurriesused for well applications. The defoamer in the present example was asiloxane product. Other examples of defoamers include glycols. Forexample, a dispersant can be included in the range of about 0.02 gal/skto about 0.1 gal/sk of cement.

An inorganic salt may be included as an additive or the water mayotherwise have salt therein, such as a brine. One of the purposes of aninorganic salt additive can be to increase the density of the cementcomposition. Examples of suitable inorganic salts include, withoutlimitation, sodium chloride, potassium chloride, and other salts.

A stabilizer (surfactant) may be included as an additive. One of thepurposes of a stabilizer is to prevent the de-emulsification of thelatex in the water of the composition.

Rheology and Fluid Loss

Rheology of the cement slurries was measured. A FANN™ model 35 is astandard instrument used to measure the rheological properties offluids. Measurement was done as per API 10B-2/ISO10426-2. Thisviscometer is a rotational viscometer with Couette geometry.

Fluid Loss was measured as follows. Solid materials were weighed andthen blended thoroughly prior to adding them to the mixing fluid. Mixingcontainer with the required mass of mix water and liquid additives wasplaced on the mixer base. The blend of solid materials was added at auniform rate within 15 seconds while mixing at 4,000 rpm. After theaddition of all solid materials to the mix water, the mixing was done at12,000 rpm for 35 seconds. Within 1 minute after mixing, the slurry wasplaced in the container of atmospheric-pressure consistometer andconditioned for 20 minutes at test temperature. A fluid loss cell wasassembled and preheated to the test temperature. The slurry was pouredinto the cell and upper valve of cell was connected to pressure line.Pressure of 1,000 psi (6,895 kPa) was applied and filtrate was collectedthrough the bottom valve of fluid loss cell. The amount of filtrate wasmeasured at the end of 30 minutes and the value was doubled.

The rheology and fluid loss analysis for the cement slurry compositionsA-E were carried out and the results are summarized in Table 3. Theresults show that the performance of SBDI latex is at least comparablewith styrene-butadiene latex.

TABLE 3 Rheology of the slurry and fluid loss Fluid Loss Slurry Fann 35Viscosity Number API Design Temperature 600 300 200 100 60 30 6 3 (ml) A80° F. (27° C.) 251 137 99 56 39 24 9 6 — 160° F. (71° C.) 126 71 49 2819 11 3 2 36 180° F. (82° C.) 128 74 48 27 20 11 4 2 40 B 80° F. (27°C.)  300+ 195 138 75 50 29 10 6 — 160° F. (71° C.) 122 86 53 28 18 9 3 242 180° F. (82° C.) 138 70 47 24 15 8 2 1 48 C 80° F. (27° C.) 296 163122 72 50 30 10 7 — 180° F. (82° C.) 164 88 63 36 25 15 5 3 28 D 80° F.(27° C.)  300+ 199 140 80 53 32 12 9 — 180° F. (82° C.) 163 92 64 36 2414 4 4 30 E 80° F. (27° C.) 296 155 109 60 39 24 10 8 — 180° F. (82° C.)285 148 108 61 42 25 8 5 46

Sedimentation

Sedimentation tests were performed as follows. A sedimentation test tubewas lightly greased inside and all joints to ensure that it wasleak-tight and so that after setting the set cement could be removedwithout damage to the tube. The tube is inert to cement and does notdeform during the course of the test. The sample slurry was poured intothe sedimentation tube. The tube was closed with a lid and placed in anautoclave cell and then 3,000 psi (20,700 kPa) pressure applied. Theslurry was allowed to cure for 24 hours at the test temperature. Aftercuring, the autoclave chamber was allowed to cool to about 120° F. (49°C.) and then the pressure was released. The tube was removed from thecell and cooled to 80° F. (27° C.) by placing it in a water bath. Theset cement was removed from the tube and marked top, middle, and bottomportions. The cement was sliced into three pieces of equal size for eachof the portions. The weight of each portion was measured in air as wellas in water. By applying the Archimedes' principle, relative density ofeach portion was calculated.

Sedimentation test results are summarized in Table 4. These results showthat the density variation of the set cement is within the acceptablelimits, that is, within 0.3 ppg (0.036 kg/1).

TABLE 4 Sedimentation test at 220° F. (104° C.) Density Sample SlurryDesign C Slurry Design D Top 16.65 ppg (1.995 kg/l) 16.73 ppg (2.005kg/l) Middle 16.76 ppg (2.008 kg/l) 16.86 ppg (2.020 kg/l) Bottom 16.90ppg (2.025 kg/l) 16.91 ppg (2.026 kg/l)

Thickening Time, Compressive Strength, and Crush Strength

Thickening time of the cement slurry comprising styrene-butadiene latexor SBDI latex and was measured at 180° F. (82° C.) and 10,500 psi(72,400 kPa).

Compressive strength development was measured using an Ultrasonic CementAnalyzer at 180° F. (82° C.). The slurry sample was poured in a cell ofan Ultrasonic Cement Analyzer. Pressure of 3,000 psi (20,700 kPa) wasapplied and the temperature schedule was programmed in the machine. Thecuring period begins with the recording of the transit time and theapplication of temperature and pressure, and continues until the test isterminated. Transit time is the time for an ultrasonic sound wave signalto travel between the transducers of the device. The transit time isshorter in a solid set cement than in an cement slurry. Change intransit time during the test period has been converted into compressivestrength by inbuilt device.

Crush strength was measured as follows. Slurry was poured in a mold of2.0 inch (5.1 cm)×2.0 inch (5.1 cm) size. The mold was placed in thecell of autoclave and applied the pressure of 3,000 psi (20,700 kPa).The temperature schedule was programmed in the machine. After curing theslurry at 180° F. (82° C.) for 96 hours, the heating chamber was allowedto cool 120° F. (49° C.) and then pressure was released. The curedcement sample removed from the mold and allowed to cool until it reaches80° F. (27° C.). The cured sample was crushed using hydraulic press tomeasure the crush strength at room temperature.

The thickening time, compressive strength, and crush strength resultsare summarized in Table 5 (see FIGS. 1-6).

TABLE 5 Compressive and crush strength of samples UCA Compressivestrength Thickening at 180° F. (82° C.) Slurry time to 70 Time to reach48 Hours *Crush Design Bc (hr:mm) 50 psi (345 kPa) Strength Strength F00:17 — — — G 00:32 — — — H  1:56 6:43 2,906 psi 5,187 psi (20,036 kPa)(35,763 kPa) I  1:54 4:39 1,498 psi 4,606 psi (10,328 kPa) (31,757 kPa)*Average value of three measurements

The results of Table 5 show that the thickening time of SBDI latexslurry is comparable to that of styrene-butadiene latex slurry. SBDIlatex provides early compressive strength of 50 psi (345 kPa) incomparison to styrene-butadiene latex. The ultimate strength at 48 hoursfor SBDI latex slurry was about half that for the styrene-butadienelatex slurry. In order to find out the value of compressive strength forlatex slurries, it is advisable to determine crush strength. Therefore,the crush strength was measured by curing the slurry at 180° F. (82° C.)for 96 hours. The results show that the crush strength of cementcomprising SBDI latex was slightly lower than that of styrene-butadienelatex. This could be due to the resiliency provided by SBDI latex to theset cement.

Mechanical Properties—Young's Modulus and Strain a Failure

Mechanical properties of the set cement samples were measured usinghydraulic press (Universal Testing Machine) equipped with extensometers.Stress-Strain data obtained from inbuilt software for both axial andradial strains. Young's modulus is slope of the liner portion of AxialStress-Axial Strain curve.

Measurements were done according to ASTM 7012-10. (1) Cement sampleswere cured in the form of cylinders with L/D ratio of 2. (2) Surface ofthe cylinders were sliced to achieve flat surface. (3) These sampleswere marked to position the extensometer. The axial extensometer wasplaced equidistance from the center. (4) Sample was tested forunconfined compressive strength and data for axial strain were captured.(5) This data was plotted as Stress versus strain. The slope of linerportion of the curve gives Young's modulus. (6) The above experimentprovides strain at failure as well. It is a strain at which the sampleundergo failure.

Cement slurries comprising styrene-butadiene latex or SBDI latex wereprepared and cured at 180° F. (82° C.), 3,000 psi (2,700 kPa), for 96hours.

The dimensions of the cured cement cylinders were 2 inches (5.1 cm) ofdiameter and 5 inches (12.7 cm) of length. The samples were crushed in ahydraulic press equipped with an extensometer. The results were analyzedto obtain Young's modulus (where 1 Mpsi equals 1 million psi), strain atfailure, and compressive strength. The results are summarized in Table 6(see FIGS. 7-8). These results show that the cement comprising SBDIlatex exhibits better resiliency than that of styrene-butadiene latex.

TABLE 6 Young's modulus of samples Slurry Design Young's Modulus Strainat failure Crush Strength H 1.63 Mpsi 0.0037 5,220 psi (11.2 × 10⁹ Pa)(36,000 kPa) I 1.14 Mpsi 0.0066 4,411 psi (7.86 × 10⁹ Pa) (30,400 kPa)

CONCLUSION

Therefore, the present disclosure is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein.

The exemplary fluids disclosed herein may directly or indirectly affectone or more components or pieces of equipment associated with thepreparation, delivery, recapture, recycling, reuse, or disposal of thedisclosed fluids. For example, the disclosed fluids may directly orindirectly affect one or more mixers, related mixing equipment, mudpits, storage facilities or units, fluid separators, heat exchangers,sensors, gauges, pumps, compressors, and the like used generate, store,monitor, regulate, or recondition the exemplary fluids. The disclosedfluids may also directly or indirectly affect any transport or deliveryequipment used to convey the fluids to a well site or downhole such as,for example, any transport vessels, conduits, pipelines, trucks,tubulars, or pipes used to fluidically move the fluids from one locationto another, any pumps, compressors, or motors (for example, topside ordownhole) used to drive the fluids into motion, any valves or relatedjoints used to regulate the pressure or flow rate of the fluids, and anysensors (i.e., pressure and temperature), gauges, or combinationsthereof, and the like. The disclosed fluids may also directly orindirectly affect the various downhole equipment and tools that may comeinto contact with the chemicals/fluids such as, but not limited to,drill string, coiled tubing, drill pipe, drill collars, mud motors,downhole motors or pumps, floats, MWD/LWD tools and related telemetryequipment, drill bits (including roller cone, PDC, natural diamond, holeopeners, reamers, and coring bits), sensors or distributed sensors,downhole heat exchangers, valves and corresponding actuation devices,tool seals, packers and other wellbore isolation devices or components,and the like.

The particular embodiments disclosed above are illustrative only, as thepresent disclosure may be modified and practiced in different butequivalent manners apparent to those skilled in the art having thebenefit of the teachings herein. It is, therefore, evident that theparticular illustrative embodiments disclosed above may be altered ormodified and all such variations are considered within the scope of thepresent disclosure.

The various elements or steps according to the disclosed elements orsteps can be combined advantageously or practiced together in variouscombinations or sub-combinations of elements or sequences of steps toincrease the efficiency and benefits that can be obtained from thedisclosure.

It will be appreciated that one or more of the above embodiments may becombined with one or more of the other embodiments, unless explicitlystated otherwise.

The illustrative disclosure can be practiced in the absence of anyelement or step that is not specifically disclosed or claimed.

Furthermore, no limitations are intended to the details of construction,composition, design, or steps herein shown, other than as described inthe claims.

What is claimed is:
 1. A composition comprising: (i) a hydraulic cement;(ii) a polymer comprising at least one styrene monomer, at least onebutyl acrylate monomer, at least one divinylbenzene monomer, and atleast one 2-isopropenyl-2-oxazoline monomer; and (iii) water.
 2. Thecomposition of claim 1, wherein the molar proportions of the monomers inthe polymer are in the range of styrene monomer about 10% to about 35%,butyl acrylate monomer about 25% to about 60%, divinylbenzene monomerabout 2% to about 15%, and 2-isopropenyl-2-oxazoline monomer about 10 toabout 40%.
 3. The composition of claim 1, wherein the polymer is in theform of a latex.
 4. The composition of claim 1, wherein the hydrauliccement comprises a Portland cement.
 5. The composition of claim 1,wherein the composition is in the form of a slurry.
 6. The compositionof claim 1, further comprising one or more additives selected from thegroup consisting of: a silica particulate, a retarder, a dispersant, aninorganic salt, a stabilizer, a defoamer, fly ash, and a weightingagent.
 7. A composition comprising: (i) a hydraulic cement; and (ii) apolymer comprising at least one monomer having an oxazoline group and atleast one butyl acrylate monomer, wherein the polymer is in the form ofa latex; and (iii) water.
 8. The composition of claim 7, wherein thepolymer further comprises at least one styrene monomer.
 9. Thecomposition of claim 7, wherein the polymer further comprises at leastone di-vinyl monomer.
 10. The composition of claim 9, wherein thedi-vinyl monomer is selected from the group consisting of: an alkanediol diacrylate, an alkane diol dimethacrylate, an alkene glycoldiacrylate, an alkene glycol dimethacrylate, an alkane diol divinylether, an alkene glycol divinylether, divinylbenzene, allylmethacrylate, and allyl acrylate.
 11. The composition of claim 10,wherein the di-vinyl monomer is a divinylbenzene monomer.
 12. Thecomposition of claim 7, wherein the at least one monomer having anoxazoline group is a 2-isopropenyl-2-oxazoline monomer.
 13. Thecomposition of claim 7, wherein the hydraulic cement comprises aPortland cement.
 14. The composition of claim 7, wherein the compositionis in the form of a slurry.
 15. The composition of claim 7, furthercomprising one or more additives selected from the group consisting of:a silica particulate, a retarder, a dispersant, an inorganic salt, astabilizer, a defoamer, fly ash, and a weighting agent.
 16. Acomposition comprising: (i) a hydraulic cement; and (ii) a polymercomprising molar proportions of one or more styrene monomers in therange of about 10% to about 35%, one or more butyl acrylate monomers inthe range of about 25% to about 60%, one or more divinylbenzene monomersin the range of about 2% to about 15%, and one or more2-isopropenyl-2-oxazoline monomers in the range of about 10% to about40%; and (iii) water.
 17. The composition of claim 16, wherein thepolymer is in the form of a latex.
 18. The composition of claim 16,wherein the hydraulic cement comprises a Portland cement.
 19. Thecomposition of claim 16, wherein the composition is in the form of aslurry.
 20. The composition of claim 16 further comprising one or moreadditives selected from the group consisting of: a silica particulate, aretarder, a dispersant, an inorganic salt, a stabilizer, a defoamer, flyash, and a weighting agent.
 21. A composition comprising: (i) ahydraulic cement; (ii) a polymer consisting essentially of at least onestyrene monomer, at least one butyl acrylate monomer, at least onedivinylbenzene monomer, and at least one 2-isopropenyl-2-oxazolinemonomer; and (iii) water.
 22. The composition of claim 21, wherein thepolymer has a specific gravity of about 1.0.